A2DP AAC support in ESP-IDF 6.1

[augied]

Hi there,

It appears that the latest beta release for ESP-IDF has added AAC support.

espressif/esp-idf@7e05593
https://github.com/espressif/esp-idf/tree/release/v6.1/examples/bluetooth/bluedroid/classic_bt/a2dp_sink_stream_aac

Does this mean that you'll be able to eventually support it as well?

Thanks!

[pschatzmann]

Committed an untested DRAFT implementation: see this example

[augied]

Wow, thanks for getting to this so quickly.

I haven't been able to get it to work yet, but that could easily be my own ignorance. I'm using the idf-release/v6.1 branch of arduino-esp32. Not sure if that's the right choice. It compiles without errors, but doesn't produce any sound and doesn't offer AAC.

Is there something I'm missing? (Likely.) Can you point me in any particular direction to start troubleshooting?

[pschatzmann]

double check the settings in sdkconfig: I think this needs to be activated...

[augied]

I was using the Arduino IDE, which apparently doesn't work with sdkconfig. So, I switched over to IDF with the arduino-esp32 component. A bit of a learning curve, but I think I've figure it out. Now, I'm getting a bunch of warnings/errors along the lines of:

arduino-audio-tools/src/AudioTools/AudioCodecs/CodecSBC.h:331:12: error: format '%d' expects argument of type 'int', but argument 4 has type 'audio_tools::sample_rate_t' {aka 'long unsigned int'} [-Werror=format=] 331 | LOGE("Invalid sample_rate: %d", info.sample_rate); | ~ | | | audio_tools::sample_rate_t {aka long unsigned int}

Followed by:

HINT: The issue is better to resolve by replacing format specifiers to 'PRI'-family macros (include <inttypes.h> header file).

[augied]

Hello again,

Using https://github.com/pschatzmann/idf-example-a2dp as a reference, I've managed to get everything working on IDF 6.1 with external codecs disabled. With external codecs enabled, I can make it compile and run, but any attempt to connect a phone immediately disconnects:

W (64538337) BT_AVCT: Out of ccbs
W (64538404) BT_APPL: bta_dm_act no entry for connected service cbs
W (64538405) BT_BTC: BTA_AV_OPEN_EVT::FAILED status: 3

It appears to be related to espressif/esp-idf#18786

I had the same issue with the IDF AAC example (https://github.com/espressif/esp-idf/tree/release/v6.1/examples/bluetooth/bluedroid/classic_bt/a2dp_sink_stream_aac) and the referenced patch fixed it. Trying to implement the same fix in ESP32-A2DP has proven to be beyond me so far. Any chance you can take a look?

Thanks

[pschatzmann]

I committed a correction

I did some tests and I confirm that AAC is working now...

[augied]

I'm still not having any luck.

I'm using the release/v6.1 branch of ESP-IDF. Switching to master resulted in a bunch of errors.

Is it necessary to include arduino-esp32? Adding it to the components folder also causes the compilation to fail.

Clearly I don't know what I'm doing here. Can you provide some details on your working configuration?

[pschatzmann]

That is an option, not a requirement: Just read the related Wiki in the AudioTools library.

[augied]

It's working now. I think I had contaminated my environment. I started fresh, and now I have AAC. Thank you so much for this great project.